Filter signal



Feb. 16, 1954 s, EHRMAN 2,669,707

FILTER SIGNAL Filed April 29, 1950 Raf FREDERICK 5. E HRMHN INVEN TOR.

ATTORNEY Patented Feb. 16,1954 la:

Frederick S. Ehrman, Fort Wayne, Ind., assignor to Bowser, Inc., Fort Wayne, Ind., a corporation of Indiana Application April 29, 1950, Serial No. 159,053

This invention relates to a filter signal. More specifically, it relates to a signal which is displayed when the filter requires attention;

It is a well known fact that filters employing a filter cartridge, such as those used for cleaning plugged to the extent that liquid is being bypassed around the filter. V

Another object of the invention is to provide a signal which is simple and inexpensive.

A further object is to provide a signal which may be reset when the cartridge has been changed.

These and other objects will become apparent from a study of this specification and the drawing which is attachedhereto and made a part hereof, and in which:

The single figure is an elevation in section with parts broken away to show the by-pass valve.

The numeral i represents a filter case having an inlet 3 and an outlet 5. The case is in two parts 6, l which have mating flanges 9, H held together by suitable fasteners [3.

The outlet in part I is provided with a suitable outlet tube i5 on which a head ii is slidably mounted and sealed by a ring it disposed in groove 20.

The part 5 is provided with a fitting l9 having a stem 2| screwed into it. This stem includes a projection 23 which enters and guides the upper head 25, and a shoulder 21 which bears on a gasket 29 to seal the upper head and stem.

A filter cartridge 30 of any suitable type is sealingly held between the heads, preferably by a spring 3|.

The projection 23 has a passage 33 which communicates at its upper end with an inlet passage in the stem and at its lower end with a by-pass chamber 31.

A magnet chamber 33 is formed in the stem above passage 33, preferably in axial alignment with 35 and 31, and has its lower end closed by a non-magnetic diaphragm M. The stem is preferably also non-magnetic.

A valve 43 is mounted in valve chamber 31 and has a stem 45 which projects through passage 33 to a point closely adjacent the diaphragm where it terminates in an armature 41 disposed 4 Claims. (01. 240439) parallel to and closely adjacent the diaphragm. A spring 49, disposed in the chamber 37, rests on a pin 5| and urges the valve 43 closed.

'A magnet 53 is slidably mounted in the chamber 39 and has a rod 55 which extends outwardly through the stem and supports at its upper end the signalbutton 57. A spring 59 which bears on the stem and button normally urges the but-'- ton, rod and magnet upwardly.

A housing 6| having sight openings 53 which may be covered by a transparent insert tube 65, enable the position of the indicator button to be determined. This housing may be frictionally engaged with a boss 61 on the stem.

Operation Liquid entering the inlet 3 normally passes through the filter cartridge and out the outlet tube l5 and outlet 5. When the filter becomes substantially impervious due to the accumulation of impurities removed from the liquid, the liquid will by-pass the cartridge by entering conduits 35, 33, will displace the valve 43 against the opposition of spring 49 and pass through chamber 37, tube 15 to outlet 5.

When the valve is thus displaced, it will draw the armature away from magnet 53 so as to reduce the force holding the magnet in place. The spring 59 overcomes this force and moves the magnet, rod 55 and signal 51 upwardly so that the latter is visible in the windows 63.

The operator perceiving the signal, knows that the cartridge should be replaced. He then shuts the required valves (not shown), removes the fasteners l3 and cover 6, removes head 25 and the filter cartridge. He will then replace the cartridge with a clean one, replace the parts mentioned above and the filter is again ready for operation. He will next remove the housing 6|, push the indicator down until the magnetic force on the armature is great enough to overcome the spring 59 so that the indicator will be held down out of sight.

The valves may be opened and the filter restored to service.

It is obvious that various changes may be made in the form, structure and arrangement of parts without departing from the spirit of the invention. Accordingly, applicant does not desire to be limited to the specific embodiment disclosed herein primarily for purposes of illustration; but instead, he desires protection falling fairly within the scope of the appended claims.

What I claim to be new and desire to protect by Letters Patent of the United States is:

1. In a filter comprising a filtering medium, the

combination of a signal having inefiective and signalling positions, means for urging said signal toward signalling position, means normally holding said signal in ineffective position, a normally closed valve means, disposed so as to be opened by the increase in pressure resulting from substantial clogging of the medium, for by-passs l quid round sa d me m and means onerated bysaid valve means for releasing said holding means.

2. In a filter comprising a filtering medium, the combination of a signal having inefieotive and signalling positions, means for urging said signal toward signalling position, means normally holding said signal in ineffective position, a nor mally closed valve means, disposed so as to be opened by the increase in pressure resulting from substantial clogging of the medium, for by-passing liquid around said medium, an armature connected to be operated by said valve means, a magnet, a si nal m u ed fo movement between in v an s gna in pos tions, means urging i s gn l towa d si nall n p si ons, said armat e in di posed os ly adiaeent the magn t. when the valve is closed, so that t e m n t for will overcome the ur in means and be ng c nnected to be moved away from said mag wh n e valve is open d so that the r s m ns will vercome he ma n tic for e- '1 :3. In a liter comprisin a f te ing medium. th combinat n f a s nal avin in fiectlv and si nalli g p s tions, means for urging said sign l t wa d s nall n position, means normall holding said signal in ineffective position, a normally closed valve means, disposed so as to be opened by the increase in pressure resulting from substantial clogging of the medium, for by-pass- .ing liquid around said medium, an armature connected to be operated by said valve means, a magnet, a non-magnetic diaphragm disposed between the armature and magnet, a signal mounted for movement between inefiective and signalling positions, means urging said signal toward signalling position, said armature being disposed closely adjacent the magnet, when the valve is closed, so that the magnetic force will overcome the urging means and being connected to be moved away from said magnet when the valve is opened so that the urging means will overcome the magnetic force.

i, n a fi t r c pr si g a filterin m d um, the combination of a signal having inefieotive and signalling positions, means for urging said signal toward signalling position, means normally holding said signal in inefiective position, a normally closed valve means, disposed so as to be opened by the increase in pressure resulting from substantial clogging of the medium, for by-passing liquid around said medium, a signal mounted for movement between ineffective and signalling positions, a magnet and an armature mounted closely adjacent each other for movement with said valve and signal, means mounting said valve means for movement, and means operated by the valve to separat said armature and magnet, means ior urging said signal toward signalling position, said urging means exerting less force than s d ma ne and armature When the latter are close proximity and exerting greater force than the magnet and armature when the latter a e s par ted b a p det rmined amount, w r by s d s nal is moved to signallin position wh the a ve. m a s moved a distance sufficient to separate said armature and signal by said m unt.

S. EHRMAN.

References Cited in the file of this patent UIH'I'ED S ATES PATENTS 

